TY - JOUR
T1 - Cultivar-to-wild population introgression in Cucurbita pepo subsp. ovifera
AU - Chung, Sang Min
AU - Decker-Walters, Deena S.
AU - Staub, Jack E.
PY - 2006/9/12
Y1 - 2006/9/12
N2 - Cultivar-to-wild population transgene flow occurs and can pose potential socio-ecological risks. In the USA, transgenic commercial squash cultivars [i.e., Cucurbita pepo subspecies ovifera var. ovifera] are cultivated in close proximity to cross-compatible wild squash taxa (i.e., vars. ozarkana and texana) that are native to theAmericas. This association provides a unique opportunity for assessing cultivarto- wild genetic introgression in this species. Thus, experiments were conducted using previously characterized random amplified polymorphic DNA (RAPD) to determine whether gene flow has occurred and whether alleles from putative introgression from cultivar-to-wild population exists in free-living populations. Free-living populations of C. pepo from the Ozark Plateau (southern Missouri, northwestern Arkansas, northeastern Oklahoma), Mississippi, Texas, Illinois, Kentucky, and Louisiana were examined using 21 RAPD primers (23 discriminatory bands). Banding morphotypes were useful for discriminating cultivated and wild populations. It appears that C. pepo populations in southeastern Texas and the Ozark Plateau are relatively homogeneous and did not have band morphotypes from cultivated types. Thus, these populations are most representative of var. texana (Texas) and var. ozarkana (the Ozark Plateau). The genetic compositions of accessions from some free-living populations, particularly in Illinois and Kentucky, suggest that squash, pumpkin, and ornamental gourd farming continue to be sources of genetic contamination for nearby wild populations. Thus, gene flow from transgenic cultivars to wild populations is likely, which, in turn, will lead to changes in the genetic structure of such populations.
AB - Cultivar-to-wild population transgene flow occurs and can pose potential socio-ecological risks. In the USA, transgenic commercial squash cultivars [i.e., Cucurbita pepo subspecies ovifera var. ovifera] are cultivated in close proximity to cross-compatible wild squash taxa (i.e., vars. ozarkana and texana) that are native to theAmericas. This association provides a unique opportunity for assessing cultivarto- wild genetic introgression in this species. Thus, experiments were conducted using previously characterized random amplified polymorphic DNA (RAPD) to determine whether gene flow has occurred and whether alleles from putative introgression from cultivar-to-wild population exists in free-living populations. Free-living populations of C. pepo from the Ozark Plateau (southern Missouri, northwestern Arkansas, northeastern Oklahoma), Mississippi, Texas, Illinois, Kentucky, and Louisiana were examined using 21 RAPD primers (23 discriminatory bands). Banding morphotypes were useful for discriminating cultivated and wild populations. It appears that C. pepo populations in southeastern Texas and the Ozark Plateau are relatively homogeneous and did not have band morphotypes from cultivated types. Thus, these populations are most representative of var. texana (Texas) and var. ozarkana (the Ozark Plateau). The genetic compositions of accessions from some free-living populations, particularly in Illinois and Kentucky, suggest that squash, pumpkin, and ornamental gourd farming continue to be sources of genetic contamination for nearby wild populations. Thus, gene flow from transgenic cultivars to wild populations is likely, which, in turn, will lead to changes in the genetic structure of such populations.
KW - Gene flow
KW - Introgression
KW - Random amplified polymorphic DNA
KW - Socio-ecological risk
UR - http://www.scopus.com/inward/record.url?scp=33751571075&partnerID=8YFLogxK
U2 - 10.1300/J153v08n01_01
DO - 10.1300/J153v08n01_01
M3 - Article
AN - SCOPUS:33751571075
SN - 1522-886X
VL - 8
SP - 1
EP - 18
JO - Journal of New Seeds
JF - Journal of New Seeds
IS - 1
ER -